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Department of Biology |
Keith
M. Howard
Assistant Professor
Ph.D Thesis: The Effect of Metalaxyl on Resistance in Populations of Phytophthora megasperma f. sp. glycinea Education:
Plant Sciences 220(Bio_220 course number) Plant Sciences Laboratory(department acronym course number) Plant Pathology 1. Production of Indole-3-Acetic Acid in
Pseudomonas solanacearum. Indole-3-acetic
acid (IAA) is an important plant hormone which is produced in this important
plant pathogen. We are interested in elucidating the precise biochemical
pathway(s) by which IAA is produced and regulated. We ultimately wish to
determine the importance of IAA as a virulence factor during pathogenesis.
Studies are being conducted using GC-Mass spectrometry to identify potential
biochemical intermediates leading to the production of IAA. 2. Nutritional parameters affecting the
production of extracellular enzymes in Colletotrichum truncatum.We are evaluating both conidia
and mycosclerotia as propagules
to be used in the control of the noxious weed, Hemp sesbania
(Sesbania exaltata).
This endemic fungus, also known as a mycoherbicide,
provides a natural alternative to reduction of chemical herbicides used in
the environment. We are studying the production and role of exported cutinases produced during the infection process with the
goal of optimizing their production. Secondly, we are evaluating mycosclerotia produced by the fungus as an effective soil
inoculum to provide more uniform control of the
weed. 3. Nutritional basis of sporulation in the biocontrol
fungus Alternaria crassa
and Alternaria cassiae.
The effects of carbon, nitrogen and trace minerals on spore morphology and
infectivity will be examined. 4. Oligosaccharide signaling in plants
as mediated by Phytophthora and Pythium spp. Cell wall
fragments from both plants and fungi can act as signaling agents to activate
a number of host defense mechanisms during invasions. Studies will be
undertaken to understand the mechanism of gene activation. Howard, K.M., Smart, M.G. and R.J. Bothast. 1993. A Novel Method of Identifying Newly
Produced Conidia in Submerged Liquid Culture. Mycologia
85: 127-130. Smart, M. G., K. M. Howard and R. J. Bothast, 1992. Effect of carbon dioxide on sporulation of Alternaria
crassa and Alternaria
cassias. Mycopathologia 118: 167-171. Schisler, D. A., K. M. Howard and R. J. Bothast, 1991. Coinoculation of
the weed Sesbania exaltata
with Colletotrichum truncatum
and epiphytic bacteria to enhance pathogen efficiency. Biological Control 1:
261-268. To the Morehouse College Homepage Department of Biology Office: 115 Hope Hall Last Updated:
Aug. 25, 03 / Porsch R. Fallen |
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